The proposed research will deal with further characterization of the mechanism by which chylomicron remnants are removed by rat liver. Studies are planned utilizing radio-iodinated chylomicron remnants and partially purified apoproteins from serum lipoproteins to study the interaction of chylomicron remanants with liver plasma membranes. Additional studies are planned to study the interaction of chylomicron remnants with the other lipoprotein classes in their serum. These will include trying to answer the question of whether chylomicron remnants can be converted to low density lipoproteins by the liver. The effect of chylomicron remnant removal on the rate of production of high density lipoproteins and very low density lipoproteins will also be studied.